The relationship between lymphocyte abnormalities, malignant lymphoma and autoimmunity in patients with Sjogren's syndrome and in New Zealand Black mice is under investigation. Our aim is to use the spontaneous occurrence of malignant lymphomas and immunologic abnormalities in the New Zealand Black mouse to understand pathogenetic events underlying lymphoid malignancy in humans. The major studies have involved a detailed analysis of T and B lymphpcytes in serum and tissue infiltrates of patients with Sjogren's syndrome, an autoimmune disease that attacks salivary and lacrimal glands. In addition, an extensive investigation of immunoglobulin determinants on tumor cell surfaces has been undertaken in a malignant lymphoma that arose spontaneously in our New Zealand Black/New Zealand White F1 mouse colony. Future studies will involve the potential diagnostic significance of beta-2 microglobulin in Sjogren's syndrome, and the importance of antibody- dependent cellular cytoxicity as a normal immunologic regulatory mechanism to limit clonal proliferation of lymphocytes.